Electric air purifiers arranged in air channels of conditioners are known.
A conventional electric air purifier disclosed in Japanese Patent Laid-Open Publication No. 2003-106552 will be described with reference to FIGS. 53 to 55. The air purifier includes holding frame 101, high-voltage power supply 102 provided at an end of holding frame 101, high-voltage terminal 103 and ground terminal 104 provided from high-voltage power supply 102, and removable filter body 106 having contact point 105 between high-voltage terminal 103 and ground terminal 104. Coil spring 107 or flat spring 108 is provided at least one of high-voltage terminal 103 and ground terminal 104. High-voltage power supply 102 is provided on holding frame 101 in a manner that each elastic tip of terminals 103 and 104 projects from partition wall 109 provided between high-voltage power supply 102 and a part through which filter body 106 is inserted.
Holding wall 110 provided at an end of holding frame 101 on the opposite side of high-voltage power supply 102 to hold filter body 106 fitted into holding frame 101. Filter body 106 is fixed between partition wall 109 and holding wall 110 in a manner that projection 111 provided on the side surface on the opposite side of contact point 105 has engagement with pit 112 provided on holding wall 110 of holding frame 101.
In the conventional air purifier, high-voltage terminal 103 connected to high-voltage power supply 102 easily collects dust, and the air purifier also has a part exposed from the structure.
Filter body 106 is, as described above, fixed between partition wall 109 and holding wall 110. When attached to or removed from the place, filter body 106 tends to have torsion due to the oblong shape, and therefore the installation work has often involved a difficulty.
Here will be described another electric dust collector having a synthetic resin-made holding frame, which is disclosed in Japanese Patent Unexamined Publication No. 2003-10731, with reference to FIGS. 56 to 58. Needle-shaped discharge electrode 1103 is provided on the side of water inlet 1102 of resin-made holding frame 1101, and then air-permeable ground electrode 1104 is provided so as to face discharge electrode 1103, furthermore, filter 1105 is located on the leeward side of ground electrode 1104. Filter unit 1106 is thus formed. When filter unit 1106 is mounted on the dust collector, high-voltage applying section 1107 applies negative high voltage to discharge electrode 1103, and ground electrode 1104 provides ground connection. Such formed high-voltage applying device 1108 is provided on the air channel in an air conditioner and the like.
In the conventional dust-collecting unit, holding frame 1101 is made of commonly used synthetic resin, which easily collects dust due to charged static electricity.
As another conventional electric dust-collecting unit, Japanese Patent Laid-Open Publication No. 2003-103196 discloses another electric dust collector. The dust collector includes, in addition to the device that applies high voltage to a dust collecting section, a sound-wave generator that enhances dust collection efficiency. The dust collector will be described with reference to FIG. 59. Dust-collecting unit 2101 contains housing 2102, discharge electrode 2103, counter-electrode 2104, and dust-collecting filter 2105. In addition, controller 2107 and switch 2108 are provided so that direct current power supply 2106 provided outside dust-collecting unit 2101 applies voltage to discharge electrode 2103 and counter-electrode 2104. Furthermore, the dust collector has sound-wave generator 2110 on side section 2109 of housing 2102, and sound-wave controller 2111 for controlling sound-wave generator 2110. With the structure above, sound wave is applied to a corona discharge area so as to enhance dust collection efficiency. Air flows in direction 2201.
In the conventional electric dust collector, direct current power supply 2106 for applying direct current to dust-collecting unit 2101, controller 2107, and switch 2108 are provided outside the dust collector. Sound-wave generator 2110 is provided on side section 2109 of housing 2102 of the dust-collecting unit and is controlled by sound-wave controller 2111. That is, direct current power supply 2106, controller 2107, switch 2108, sound-wave generator 2110, and sound-wave controller 2111 can suffer mutual noise interference. The installation of these components away from dust-collecting unit housing 2102 not only increases the wiring in length for connecting these components, but also complicates measures against dust collection on each component.
As still another electric dust collection unit, Japanese Patent No. 2856580 discloses an air purifier. Changing the shape of an elastic portion provided on a filter opens or closes a power circuit for a high-voltage power supply unit. The air purifier will be described with reference to FIGS. 60 and 61. The air purifier includes body 3102 having removable front panel 3101, removable pre-filter 3103 provided on body 3102, high-voltage ionizier 3104 for removing dust in the air passing through pre-filter 3103, elastic portion 3105 provided on pre-filter 3103, and detecting switch 3106 for detecting altered elastic portion 3105. Elastic portion 3105 provided at pre-filter 3103 bends by being pushed by front panel 3101 when pre-filter 3103 is mounted on body 3102. Detecting switch 3106 detects the deformation of elastic portion 3105. Detecting switch 3106 does not detect the deformation, a power supply to high-voltage ionizer 3104 is turned off.
In this conventional air purifier, elastic portion 3105 provided on pre-filter 3103 bends toward detecting switch 3106 by being pushed by front panel 3101 when front panel 3101 is fixed to the body. If front panel 3101, pre-filter 3103, and detecting switch 3106 have positional variations, detecting switch 3106 cannot be activated accurately.
Besides, exposed detecting switch 3106 easily collects dust, which can cause faulty connections.
As yet another electric dust-collecting unit, Japanese Patent Laid-Open Publication No. 2003-106552 discloses an electric air purifier for an air conditioner. The electric air purifier will be described with reference to FIG. 62. The air purifier includes holding frame 4101, high-voltage power supply 4102 provided at an end of holding frame 4101, high-voltage terminal 4103 and ground terminal 4104 provided from high-voltage power supply 4102, contact point 4105 of high-voltage terminal 4103 and ground terminal 4104, and filter body 4106 removably provided to holding frame 4101.
In this conventional electric air purifier, high-voltage power supply 4102 is provided on holding frame 4101, which is seen on the left side in the drawing, and filter body 4106 is fixed on the right side of high-voltage power supply 4102. Due to positional constraint in mounting on an air conditioner, high-voltage power supply 4102 cannot be provided on the right side of holding frame 4101.
High-voltage terminal 4103 and ground terminal 4104 are provided on only one side of the right and left sides of filter body 4106 to be mounted on holding frame 4101. Therefore, when filter body 4106 is removed from holding frame 4101, filter body 4106 tends to have torsion, due to resistance of high-voltage terminal 4103 and ground terminal 4104, so that the removing work has often involved a difficulty.